BLOOD DONORS AND BLOOD COLLECTION
Utility of zinc protoporphyrin in management of whole blood
Saurabh Zalpuri ,
Pieternel C.M. Pasker-de Jong,
Dorine W. Swinkels,
Katja van den Hurk,
Wim L.A.M. de Kort,
Marian G.J. van Kraaij,
and Paulus A.H. van Noord
Deferral for low hemoglobin (Hb)
increases the likelihood that donors do not return for
future donations. Zinc protoporphyrin (ZPP) has been
described as a sensitive marker of iron-deficient
erythropoiesis, before Hb decreases. It is a relatively
cheap, rapid, and easy-to-perform measurement in a
drop of whole blood. To assess the utility of ZPP
measurement in donor management we examined
whether ZPP and Hb levels among first-time donors differ
from repeat donors. We further explored whether ZPP
increases over subsequent donations at a donor
population level and whether increasing ZPP levels
coincide with decreasing Hb levels and donor deferral.
STUDY DESIGN AND METHODS:
We included first-
time (n 5 4983) and repeat (n 5 3533) whole blood
donors from the ZPP and Iron in the Netherlands Cohort
(ZINC) study. ZPP and Hb were measured at each
subsequent donation during a 4-year period after
inclusion in the study.
Median ZPP levels were higher in repeat
than in first-time donors. In first-time donors, especially
women, ZPP levels were increased with a corresponding
decline in Hb levels over subsequent donations. ZPP
levels were increased among first-time donors deferred
for low Hb.
Our results suggest that adding ZPP to
Hb measurements in the daily blood collection setting,
especially for first-time donors and first-time female
donors may add to the identification of a donor
subpopulation with low functional iron stores.
n the Netherlands and many other countries, the
hemoglobin (Hb) level is measured at each visit
before whole blood donation to assess whether the
donor is capable of blood donation. When this Hb
level is below 7.8 and 8.4 mmol/L (12.5 and 13.5 g/dL) for
female and male donors, respectively, the donor will be
deferred for donation. Hb concentration is considered a
proxy for the iron status of the donor. However, in healthy
blood donors Hb does not decline until iron stores are
A variable that has been reported to
more accurately reflect the imbalance between bone mar-
row iron needs and supplies is zinc protoporphyrin
When there is insufficient iron, zinc instead of iron
will be incorporated into protoporphyrin IX in the last
step of heme synthesis, leading to the formation of ZPP.
It was as early as 1987 when it was found that ZPP
formation is an early response to body loss of iron.
ABBREVIATIONS: ZINC study 5 ZPP and Iron in the
Netherlands Cohort study; ZPP 5 zinc protoporphyrin.
Department Donor Studies, Sanquin Research,
Amsterdam, the Netherlands; the
Laboratory, Department of Laboratory Medicine, Radboud
University Medical Center, Nijmegen, the Netherlands; the
Departments of Donor Affairs and Transfusion Medicine,
Sanquin Blood Bank, Amsterdam, the Netherlands; and the
Meander Academy, Meander Medical Center, Amersfoort, the
Address reprint requests to: Saurabh Zalpuri, Sanquin
Blood Supply, Plesmanlaan 125, 1066 CX Amsterdam, the Neth-
erlands; e-mail: firstname.lastname@example.org.
NS and SZ contributed equally as joint first authors.
This work was funded by Sanquin Blood Supply with no
involvement in the design, collection, analysis, and interpreta-
tion of the study data.
Received for publication July 13, 2017; revision received
October 24, 2017; and accepted October 24, 2017.
692 TRANSFUSION Volume 58, March 2018